Amino-salicylic acid sulphate prepn. - from ethyl nitro-salicylate by sulphation, hydrolysis and catalytic redn.

摘要

5-Amino salicylic acid o-sulphate of formula (I) of formula (I) for use in treatment of diarrhoea, ulcerous colitis and Crohn disease, is made by (a) reacting ethyl 5-nitro salicylate (II) with sulphuric acid in presence of dicyclohexyl carbo-diimide to give (III); (b) hydrolysing with NaOH or KOH to obtain the acid (IV); and (c) reducing by catalytic hydrogenation to reducing (I).